The present invention relates to designing environmental control systems and, more particularly, to sizing spot cooling and heating systems for achieving and maintaining localized thermal control.
Spot cooling is the cooling of a specific target or area within a room, factory or other space, by delivering cool air directly to the target or “spot” that needs to be cooled. Similarly, spot heating is the heating of a specific target or area within a room, factory or other structure, by delivering warm air directly to the target or “spot” that needs to be heated. In both cases, because the cooling/heating air is delivered directly to the target or spot that needs to be temperature controlled, effective thermal control of the target or spot can be achieved without the expensive and inefficient undertaking of cooling or heating the entire room, factory or other space in which the target is located.
Spot cooling and heating typically involve only minimal installation and are particularly beneficial in situations where it would unduly expensive or inefficient to cool or heat by standard air-conditioning or heating systems. For example, spot cooling and heating systems are commonly used in industrial environments, such as large, open areas in factories and warehouses. Spot cooling and heating systems are ideal in such applications because only the target that needs cooling (or heating) is cooled (or heated), not the entire room, building or other large space in which the target is located. However, their uses are not necessarily limited to industrial environments. Spot cooling and heating systems may also be used in commercial and residential environments, such as offices, computer rooms, tents, boardrooms and homes. In addition, spot cooling and heating systems are useful in outdoor events, and are commonly used as emergency backups. Also, typically, spot cooling and heating systems are relatively adaptable and flexible, which permits customization to suit a particular target's needs, and permits reconfiguration when targets change, e.g., when workers in a production line move within their stations or as the production line is modified.
Thus, spot cooling and spot heating provides an effective and relatively inexpensive solution to maintaining thermal comfort and safety, and eliminates the need to air condition or heat an entire factory floor or other ambient space in which a target is located. However, it is still necessary for a design engineer, plant manager or HVAC technician to design and/or select a spot cooling or spot heating system of appropriate size and capacity for a given application. There is no “one size fits all” solution that will be optimal in all situations. Various factors need to be considered by the design engineer, plant manager or technician which selecting an appropriate spot cooling or heating system, such as the desired temperature of the target, the temperature of discharge air that is to be discharged from the spot cooling or spot heating system toward the target, the temperature of the ambient air surrounding the target, the distance between the discharge duct(s) of the spot cooling or spot heating system and the target (sometimes referred to as “throw”), the desired coverage area, the volumetric flow rate of the discharge air, the number and relative location(s) of targets to be temperature controlled by the system (e.g., the number of workers or workstations), and the humidity and air currents of the ambient air surrounding the target. Of course, depending on the particular application and its unique needs, other factors may need to be considered by the design engineer, plant manager or technician, but these are believed by the inventors to be the primary factors that should be considered in designing and sizing a spot cooling or heating system.
Conventionally, to size and select a proper spot cooling system for a given application, the design engineer, plant manager or technician determines the appropriate size, capacity and other parameters of the system by utilizing known principles of fluid mechanics, including a variety of complex mathematical equations, to manually calculate optimal parameters for each given application. Even if the designer possesses the necessary background and knowledge in the art of fluid mechanics and HVAC system design, the process of manually calculating all of the optimal parameters for every possible system variation of a given application would be cumbersome, time consuming, and potentially cost-prohibitive. Unfortunately, what sometimes happens in practice is that the engineer, plant manager or technician attempts to select system parameters by guessing what parameters will be optimal or by trial and error, either because the person designing or selecting the system does not have the necessary background and knowledge in the art of fluid mechanics or HVAC design or because the person does not want to take the time and effort that would be necessary to manually calculate the optimal parameters. Occasionally, the person designing or selecting the system will simply “over design” to ensure that the resulting system clearly has the capacity to achieve the desired result for a given application, but this defeats at least some of the reasons for using spot cooling and heating systems over conventional HVAC systems in the first place (e.g., cost savings, efficiency, cooling the worker instead of the workspace, etc.).
Thus, there is a need for a less cumbersome, less expensive and more efficient manner of determining optimal characteristics of an environmental control system, such as a spot cooling or spot heating system, without the need to process complex mathematical equations or navigate complicated fluid mechanics principles, to manually calculate optimal system parameters for each given application or variation thereof.